/*
 * TLSv1 client - write handshake message
 * Copyright (c) 2006-2011, Jouni Malinen <j@w1.fi>
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#include "wpa/includes.h"

#include "wpa/common.h"
#include "crypto/md5.h"
#include "crypto/sha1.h"
#include "crypto/sha256.h"
#include "crypto/random.h"
#include "wpa2/tls/tls.h"
#include "wpa2/tls/x509v3.h"
#include "wpa2/tls/tlsv1_common.h"
#include "wpa2/tls/tlsv1_record.h"
#include "wpa2/tls/tlsv1_client.h"
#include "wpa2/tls/tlsv1_client_i.h"

#ifdef MEMLEAK_DEBUG
static const char mem_debug_file[] ICACHE_RODATA_ATTR = __FILE__;
#endif

static size_t tls_client_cert_chain_der_len(struct tlsv1_client* conn)
{
    size_t len = 0;
    struct x509_certificate* cert;

    if (conn->cred == NULL) {
        return 0;
    }

    cert = conn->cred->cert;

    while (cert) {
        len += 3 + cert->cert_len;

        if (x509_certificate_self_signed(cert)) {
            break;
        }

        cert = x509_certificate_get_subject(conn->cred->trusted_certs,
                                            &cert->issuer);
    }

    return len;
}


u8* tls_send_client_hello(struct tlsv1_client* conn, size_t* out_len)
{
    u8* hello, *end, *pos, *hs_length, *hs_start, *rhdr;
    struct os_time now;
    size_t len, i;

    wpa_printf(MSG_DEBUG, "TLSv1: Send ClientHello");
    *out_len = 0;

    os_get_time(&now);
    WPA_PUT_BE32(conn->client_random, now.sec);

    if (random_get_bytes(conn->client_random + 4, TLS_RANDOM_LEN - 4)) {
        wpa_printf(MSG_ERROR, "TLSv1: Could not generate "
                   "client_random");
        return NULL;
    }

    wpa_hexdump(MSG_MSGDUMP, "TLSv1: client_random",
                conn->client_random, TLS_RANDOM_LEN);

    len = 100 + conn->num_cipher_suites * 2 + conn->client_hello_ext_len;
    hello = os_malloc(len);

    if (hello == NULL) {
        return NULL;
    }

    end = hello + len;

    rhdr = hello;
    pos = rhdr + TLS_RECORD_HEADER_LEN;

    /* opaque fragment[TLSPlaintext.length] */

    /* Handshake */
    hs_start = pos;
    /* HandshakeType msg_type */
    *pos++ = TLS_HANDSHAKE_TYPE_CLIENT_HELLO;
    /* uint24 length (to be filled) */
    hs_length = pos;
    pos += 3;
    /* body - ClientHello */
    /* ProtocolVersion client_version */
    WPA_PUT_BE16(pos, TLS_VERSION);
    pos += 2;
    /* Random random: uint32 gmt_unix_time, opaque random_bytes */
    os_memcpy(pos, conn->client_random, TLS_RANDOM_LEN);
    pos += TLS_RANDOM_LEN;
    /* SessionID session_id */
    *pos++ = conn->session_id_len;
    os_memcpy(pos, conn->session_id, conn->session_id_len);
    pos += conn->session_id_len;
    /* CipherSuite cipher_suites<2..2^16-1> */
    WPA_PUT_BE16(pos, 2 * conn->num_cipher_suites);
    pos += 2;

    for (i = 0; i < conn->num_cipher_suites; i++) {
        WPA_PUT_BE16(pos, conn->cipher_suites[i]);
        pos += 2;
    }

    /* CompressionMethod compression_methods<1..2^8-1> */
    *pos++ = 1;
    *pos++ = TLS_COMPRESSION_NULL;

    if (conn->client_hello_ext) {
        os_memcpy(pos, conn->client_hello_ext,
                  conn->client_hello_ext_len);
        pos += conn->client_hello_ext_len;
    }

    WPA_PUT_BE24(hs_length, pos - hs_length - 3);
    tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);

    if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
                          rhdr, end - rhdr, hs_start, pos - hs_start,
                          out_len) < 0) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to create TLS record");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        os_free(hello);
        return NULL;
    }

    conn->state = SERVER_HELLO;

    return hello;
}


static int tls_write_client_certificate(struct tlsv1_client* conn,
                                        u8** msgpos, u8* end)
{
    u8* pos, *rhdr, *hs_start, *hs_length, *cert_start;
    size_t rlen;
    struct x509_certificate* cert;

    pos = *msgpos;

    wpa_printf(MSG_DEBUG, "TLSv1: Send Certificate");
    rhdr = pos;
    pos += TLS_RECORD_HEADER_LEN;

    /* opaque fragment[TLSPlaintext.length] */

    /* Handshake */
    hs_start = pos;
    /* HandshakeType msg_type */
    *pos++ = TLS_HANDSHAKE_TYPE_CERTIFICATE;
    /* uint24 length (to be filled) */
    hs_length = pos;
    pos += 3;
    /* body - Certificate */
    /* uint24 length (to be filled) */
    cert_start = pos;
    pos += 3;
    cert = conn->cred ? conn->cred->cert : NULL;

    while (cert) {
        if (pos + 3 + cert->cert_len > end) {
            wpa_printf(MSG_DEBUG, "TLSv1: Not enough buffer space "
                       "for Certificate (cert_len=%lu left=%lu)",
                       (unsigned long) cert->cert_len,
                       (unsigned long)(end - pos));
            tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                      TLS_ALERT_INTERNAL_ERROR);
            return -1;
        }

        WPA_PUT_BE24(pos, cert->cert_len);
        pos += 3;
        os_memcpy(pos, cert->cert_start, cert->cert_len);
        pos += cert->cert_len;

        if (x509_certificate_self_signed(cert)) {
            break;
        }

        cert = x509_certificate_get_subject(conn->cred->trusted_certs,
                                            &cert->issuer);
    }

    if (conn->cred == NULL || cert == conn->cred->cert || cert == NULL) {
        /*
         * Client was not configured with all the needed certificates
         * to form a full certificate chain. The server may fail to
         * validate the chain unless it is configured with all the
         * missing CA certificates.
         */
        wpa_printf(MSG_DEBUG, "TLSv1: Full client certificate chain "
                   "not configured - validation may fail");
    }

    WPA_PUT_BE24(cert_start, pos - cert_start - 3);

    WPA_PUT_BE24(hs_length, pos - hs_length - 3);

    if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
                          rhdr, end - rhdr, hs_start, pos - hs_start,
                          &rlen) < 0) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate a record");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        return -1;
    }

    pos = rhdr + rlen;

    tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);

    *msgpos = pos;

    return 0;
}


static int tlsv1_key_x_anon_dh(struct tlsv1_client* conn, u8** pos, u8* end)
{
    /* ClientDiffieHellmanPublic */
    u8* csecret, *csecret_start, *dh_yc, *shared;
    size_t csecret_len, dh_yc_len, shared_len;

    csecret_len = conn->dh_p_len;
    csecret = os_malloc(csecret_len);

    if (csecret == NULL) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to allocate "
                   "memory for Yc (Diffie-Hellman)");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        return -1;
    }

    if (random_get_bytes(csecret, csecret_len)) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to get random "
                   "data for Diffie-Hellman");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        os_free(csecret);
        return -1;
    }

    if (os_memcmp(csecret, conn->dh_p, csecret_len) > 0) {
        csecret[0] = 0;    /* make sure Yc < p */
    }

    csecret_start = csecret;

    while (csecret_len > 1 && *csecret_start == 0) {
        csecret_start++;
        csecret_len--;
    }

    wpa_hexdump_key(MSG_DEBUG, "TLSv1: DH client's secret value",
                    csecret_start, csecret_len);

    /* Yc = g^csecret mod p */
    dh_yc_len = conn->dh_p_len;
    dh_yc = os_malloc(dh_yc_len);

    if (dh_yc == NULL) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to allocate "
                   "memory for Diffie-Hellman");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        os_free(csecret);
        return -1;
    }

    if (crypto_mod_exp(conn->dh_g, conn->dh_g_len,
                       csecret_start, csecret_len,
                       conn->dh_p, conn->dh_p_len,
                       dh_yc, &dh_yc_len)) {
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        os_free(csecret);
        os_free(dh_yc);
        return -1;
    }

    wpa_hexdump(MSG_DEBUG, "TLSv1: DH Yc (client's public value)",
                dh_yc, dh_yc_len);

    WPA_PUT_BE16(*pos, dh_yc_len);
    *pos += 2;

    if (*pos + dh_yc_len > end) {
        wpa_printf(MSG_DEBUG, "TLSv1: Not enough room in the "
                   "message buffer for Yc");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        os_free(csecret);
        os_free(dh_yc);
        return -1;
    }

    os_memcpy(*pos, dh_yc, dh_yc_len);
    *pos += dh_yc_len;
    os_free(dh_yc);

    shared_len = conn->dh_p_len;
    shared = os_malloc(shared_len);

    if (shared == NULL) {
        wpa_printf(MSG_DEBUG, "TLSv1: Could not allocate memory for "
                   "DH");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        os_free(csecret);
        return -1;
    }

    /* shared = Ys^csecret mod p */
    if (crypto_mod_exp(conn->dh_ys, conn->dh_ys_len,
                       csecret_start, csecret_len,
                       conn->dh_p, conn->dh_p_len,
                       shared, &shared_len)) {
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        os_free(csecret);
        os_free(shared);
        return -1;
    }

    wpa_hexdump_key(MSG_DEBUG, "TLSv1: Shared secret from DH key exchange",
                    shared, shared_len);

    os_memset(csecret_start, 0, csecret_len);
    os_free(csecret);

    if (tls_derive_keys(conn, shared, shared_len)) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive keys");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        os_free(shared);
        return -1;
    }

    os_memset(shared, 0, shared_len);
    os_free(shared);
    tlsv1_client_free_dh(conn);
    return 0;
}


static int tlsv1_key_x_rsa(struct tlsv1_client* conn, u8** pos, u8* end)
{
    u8 pre_master_secret[TLS_PRE_MASTER_SECRET_LEN];
    size_t clen;
    int res;

    if (tls_derive_pre_master_secret(pre_master_secret) < 0 ||
            tls_derive_keys(conn, pre_master_secret,
                            TLS_PRE_MASTER_SECRET_LEN)) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive keys");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        return -1;
    }

    /* EncryptedPreMasterSecret */
    if (conn->server_rsa_key == NULL) {
        wpa_printf(MSG_DEBUG, "TLSv1: No server RSA key to "
                   "use for encrypting pre-master secret");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        return -1;
    }

    /* RSA encrypted value is encoded with PKCS #1 v1.5 block type 2. */
    *pos += 2;
    clen = end - *pos;
    res = crypto_public_key_encrypt_pkcs1_v15(
              conn->server_rsa_key,
              pre_master_secret, TLS_PRE_MASTER_SECRET_LEN,
              *pos, &clen);
    os_memset(pre_master_secret, 0, TLS_PRE_MASTER_SECRET_LEN);

    if (res < 0) {
        wpa_printf(MSG_DEBUG, "TLSv1: RSA encryption failed");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        return -1;
    }

    WPA_PUT_BE16(*pos - 2, clen);
    wpa_hexdump(MSG_MSGDUMP, "TLSv1: Encrypted pre_master_secret",
                *pos, clen);
    *pos += clen;

    return 0;
}


static int tls_write_client_key_exchange(struct tlsv1_client* conn,
        u8** msgpos, u8* end)
{
    u8* pos, *rhdr, *hs_start, *hs_length;
    size_t rlen;
    tls_key_exchange keyx;
    const struct tls_cipher_suite* suite;

    suite = tls_get_cipher_suite(conn->rl.cipher_suite);

    if (suite == NULL) {
        keyx = TLS_KEY_X_NULL;
    } else {
        keyx = suite->key_exchange;
    }

    pos = *msgpos;

    wpa_printf(MSG_DEBUG, "TLSv1: Send ClientKeyExchange");

    rhdr = pos;
    pos += TLS_RECORD_HEADER_LEN;

    /* opaque fragment[TLSPlaintext.length] */

    /* Handshake */
    hs_start = pos;
    /* HandshakeType msg_type */
    *pos++ = TLS_HANDSHAKE_TYPE_CLIENT_KEY_EXCHANGE;
    /* uint24 length (to be filled) */
    hs_length = pos;
    pos += 3;

    /* body - ClientKeyExchange */
    if (keyx == TLS_KEY_X_DH_anon) {
        if (tlsv1_key_x_anon_dh(conn, &pos, end) < 0) {
            return -1;
        }
    } else {
        if (tlsv1_key_x_rsa(conn, &pos, end) < 0) {
            return -1;
        }
    }

    WPA_PUT_BE24(hs_length, pos - hs_length - 3);

    if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
                          rhdr, end - rhdr, hs_start, pos - hs_start,
                          &rlen) < 0) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        return -1;
    }

    pos = rhdr + rlen;
    tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);

    *msgpos = pos;

    return 0;
}


static int tls_write_client_certificate_verify(struct tlsv1_client* conn,
        u8** msgpos, u8* end)
{
    u8* pos, *rhdr, *hs_start, *hs_length, *signed_start;
    size_t rlen, hlen, clen;
    u8 hash[100], *hpos;
    enum { SIGN_ALG_RSA, SIGN_ALG_DSA } alg = SIGN_ALG_RSA;

    pos = *msgpos;

    wpa_printf(MSG_DEBUG, "TLSv1: Send CertificateVerify");
    rhdr = pos;
    pos += TLS_RECORD_HEADER_LEN;

    /* Handshake */
    hs_start = pos;
    /* HandshakeType msg_type */
    *pos++ = TLS_HANDSHAKE_TYPE_CERTIFICATE_VERIFY;
    /* uint24 length (to be filled) */
    hs_length = pos;
    pos += 3;

    /*
     * RFC 2246: 7.4.3 and 7.4.8:
     * Signature signature
     *
     * RSA:
     * digitally-signed struct {
     *     opaque md5_hash[16];
     *     opaque sha_hash[20];
     * };
     *
     * DSA:
     * digitally-signed struct {
     *     opaque sha_hash[20];
     * };
     *
     * The hash values are calculated over all handshake messages sent or
     * received starting at ClientHello up to, but not including, this
     * CertificateVerify message, including the type and length fields of
     * the handshake messages.
     */

    hpos = hash;

#ifdef CONFIG_TLSV12

    if (conn->rl.tls_version == TLS_VERSION_1_2) {
        hlen = SHA256_MAC_LEN;

        if (conn->verify.sha256_cert == NULL ||
                crypto_hash_finish(conn->verify.sha256_cert, hpos, &hlen) <
                0) {
            conn->verify.sha256_cert = NULL;
            tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                      TLS_ALERT_INTERNAL_ERROR);
            return -1;
        }

        conn->verify.sha256_cert = NULL;

        /*
         * RFC 3447, A.2.4 RSASSA-PKCS1-v1_5
         *
         * DigestInfo ::= SEQUENCE {
         *   digestAlgorithm DigestAlgorithm,
         *   digest OCTET STRING
         * }
         *
         * SHA-256 OID: sha256WithRSAEncryption ::= {pkcs-1 11}
         *
         * DER encoded DigestInfo for SHA256 per RFC 3447:
         * 30 31 30 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04 20 ||
         * H
         */
        os_memmove(hash + 19, hash, hlen);
        hlen += 19;
        os_memcpy(hash, "\x30\x31\x30\x0d\x06\x09\x60\x86\x48\x01\x65"
                  "\x03\x04\x02\x01\x05\x00\x04\x20", 19);
    } else {
#endif /* CONFIG_TLSV12 */

        if (alg == SIGN_ALG_RSA) {
            hlen = MD5_MAC_LEN;

            if (conn->verify.md5_cert == NULL ||
                    crypto_hash_finish(conn->verify.md5_cert, hpos, &hlen) < 0) {
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_INTERNAL_ERROR);
                conn->verify.md5_cert = NULL;
                crypto_hash_finish(conn->verify.sha1_cert, NULL, NULL);
                conn->verify.sha1_cert = NULL;
                return -1;
            }

            hpos += MD5_MAC_LEN;
        } else {
            crypto_hash_finish(conn->verify.md5_cert, NULL, NULL);
        }

        conn->verify.md5_cert = NULL;
        hlen = SHA1_MAC_LEN;

        if (conn->verify.sha1_cert == NULL ||
                crypto_hash_finish(conn->verify.sha1_cert, hpos, &hlen) < 0) {
            conn->verify.sha1_cert = NULL;
            tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                      TLS_ALERT_INTERNAL_ERROR);
            return -1;
        }

        conn->verify.sha1_cert = NULL;

        if (alg == SIGN_ALG_RSA) {
            hlen += MD5_MAC_LEN;
        }

#ifdef CONFIG_TLSV12
    }

#endif /* CONFIG_TLSV12 */

    wpa_hexdump(MSG_MSGDUMP, "TLSv1: CertificateVerify hash", hash, hlen);

#ifdef CONFIG_TLSV12

    if (conn->rl.tls_version >= TLS_VERSION_1_2) {
        /*
         * RFC 5246, 4.7:
         * TLS v1.2 adds explicit indication of the used signature and
         * hash algorithms.
         *
         * struct {
         *   HashAlgorithm hash;
         *   SignatureAlgorithm signature;
         * } SignatureAndHashAlgorithm;
         */
        *pos++ = TLS_HASH_ALG_SHA256;
        *pos++ = TLS_SIGN_ALG_RSA;
    }

#endif /* CONFIG_TLSV12 */

    /*
     * RFC 2246, 4.7:
     * In digital signing, one-way hash functions are used as input for a
     * signing algorithm. A digitally-signed element is encoded as an
     * opaque vector <0..2^16-1>, where the length is specified by the
     * signing algorithm and key.
     *
     * In RSA signing, a 36-byte structure of two hashes (one SHA and one
     * MD5) is signed (encrypted with the private key). It is encoded with
     * PKCS #1 block type 0 or type 1 as described in [PKCS1].
     */
    signed_start = pos; /* length to be filled */
    pos += 2;
    clen = end - pos;

    if (conn->cred == NULL ||
            crypto_private_key_sign_pkcs1(conn->cred->key, hash, hlen,
                                          pos, &clen) < 0) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to sign hash (PKCS #1)");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        return -1;
    }

    WPA_PUT_BE16(signed_start, clen);

    pos += clen;

    WPA_PUT_BE24(hs_length, pos - hs_length - 3);

    if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
                          rhdr, end - rhdr, hs_start, pos - hs_start,
                          &rlen) < 0) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate a record");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        return -1;
    }

    pos = rhdr + rlen;

    tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);

    *msgpos = pos;

    return 0;
}


static int tls_write_client_change_cipher_spec(struct tlsv1_client* conn,
        u8** msgpos, u8* end)
{
    size_t rlen;
    u8 payload[1];

    wpa_printf(MSG_DEBUG, "TLSv1: Send ChangeCipherSpec");

    payload[0] = TLS_CHANGE_CIPHER_SPEC;

    if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC,
                          *msgpos, end - *msgpos, payload, sizeof(payload),
                          &rlen) < 0) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        return -1;
    }

    if (tlsv1_record_change_write_cipher(&conn->rl) < 0) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to set write cipher for "
                   "record layer");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        return -1;
    }

    *msgpos += rlen;

    return 0;
}


static int tls_write_client_finished(struct tlsv1_client* conn,
                                     u8** msgpos, u8* end)
{
    u8* pos, *hs_start;
    size_t rlen, hlen;
    u8 verify_data[1 + 3 + TLS_VERIFY_DATA_LEN];
    u8 hash[MD5_MAC_LEN + SHA1_MAC_LEN];

    wpa_printf(MSG_DEBUG, "TLSv1: Send Finished");

    /* Encrypted Handshake Message: Finished */

#ifdef CONFIG_TLSV12

    if (conn->rl.tls_version >= TLS_VERSION_1_2) {
        hlen = SHA256_MAC_LEN;

        if (conn->verify.sha256_client == NULL ||
                crypto_hash_finish(conn->verify.sha256_client, hash, &hlen)
                < 0) {
            tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                      TLS_ALERT_INTERNAL_ERROR);
            conn->verify.sha256_client = NULL;
            return -1;
        }

        conn->verify.sha256_client = NULL;
    } else {
#endif /* CONFIG_TLSV12 */

        hlen = MD5_MAC_LEN;

        if (conn->verify.md5_client == NULL ||
                crypto_hash_finish(conn->verify.md5_client, hash, &hlen) < 0) {
            tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                      TLS_ALERT_INTERNAL_ERROR);
            conn->verify.md5_client = NULL;
            crypto_hash_finish(conn->verify.sha1_client, NULL, NULL);
            conn->verify.sha1_client = NULL;
            return -1;
        }

        conn->verify.md5_client = NULL;
        hlen = SHA1_MAC_LEN;

        if (conn->verify.sha1_client == NULL ||
                crypto_hash_finish(conn->verify.sha1_client, hash + MD5_MAC_LEN,
                                   &hlen) < 0) {
            conn->verify.sha1_client = NULL;
            tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                      TLS_ALERT_INTERNAL_ERROR);
            return -1;
        }

        conn->verify.sha1_client = NULL;
        hlen = MD5_MAC_LEN + SHA1_MAC_LEN;

#ifdef CONFIG_TLSV12
    }

#endif /* CONFIG_TLSV12 */

    if (tls_prf(conn->rl.tls_version,
                conn->master_secret, TLS_MASTER_SECRET_LEN,
                "client finished", hash, hlen,
                verify_data + 1 + 3, TLS_VERIFY_DATA_LEN)) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate verify_data");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        return -1;
    }

    wpa_hexdump_key(MSG_DEBUG, "TLSv1: verify_data (client)",
                    verify_data + 1 + 3, TLS_VERIFY_DATA_LEN);

    /* Handshake */
    pos = hs_start = verify_data;
    /* HandshakeType msg_type */
    *pos++ = TLS_HANDSHAKE_TYPE_FINISHED;
    /* uint24 length */
    WPA_PUT_BE24(pos, TLS_VERIFY_DATA_LEN);
    pos += 3;
    pos += TLS_VERIFY_DATA_LEN; /* verify_data already in place */
    tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);

    if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
                          *msgpos, end - *msgpos, hs_start, pos - hs_start,
                          &rlen) < 0) {
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                  TLS_ALERT_INTERNAL_ERROR);
        return -1;
    }

    *msgpos += rlen;

    return 0;
}


static u8* tls_send_client_key_exchange(struct tlsv1_client* conn,
                                        size_t* out_len)
{
    u8* msg, *end, *pos;
    size_t msglen;

    *out_len = 0;

    msglen = 2000;

    if (conn->certificate_requested) {
        msglen += tls_client_cert_chain_der_len(conn);
    }

    msg = os_malloc(msglen);

    if (msg == NULL) {
        return NULL;
    }

    pos = msg;
    end = msg + msglen;

    if (conn->certificate_requested) {
        if (tls_write_client_certificate(conn, &pos, end) < 0) {
            os_free(msg);
            return NULL;
        }
    }

    if (tls_write_client_key_exchange(conn, &pos, end) < 0 ||
            (conn->certificate_requested && conn->cred && conn->cred->key &&
             tls_write_client_certificate_verify(conn, &pos, end) < 0) ||
            tls_write_client_change_cipher_spec(conn, &pos, end) < 0 ||
            tls_write_client_finished(conn, &pos, end) < 0) {
        os_free(msg);
        return NULL;
    }

    *out_len = pos - msg;

    conn->state = SERVER_CHANGE_CIPHER_SPEC;

    return msg;
}


static u8* tls_send_change_cipher_spec(struct tlsv1_client* conn,
                                       size_t* out_len)
{
    u8* msg, *end, *pos;

    *out_len = 0;

    msg = os_malloc(1000);

    if (msg == NULL) {
        return NULL;
    }

    pos = msg;
    end = msg + 1000;

    if (tls_write_client_change_cipher_spec(conn, &pos, end) < 0 ||
            tls_write_client_finished(conn, &pos, end) < 0) {
        os_free(msg);
        return NULL;
    }

    *out_len = pos - msg;

    wpa_printf(MSG_DEBUG, "TLSv1: Session resumption completed "
               "successfully");
    conn->state = ESTABLISHED;

    return msg;
}


u8* tlsv1_client_handshake_write(struct tlsv1_client* conn, size_t* out_len,
                                 int no_appl_data)
{
    switch (conn->state) {
        case CLIENT_KEY_EXCHANGE:
            return tls_send_client_key_exchange(conn, out_len);

        case CHANGE_CIPHER_SPEC:
            return tls_send_change_cipher_spec(conn, out_len);

        case ACK_FINISHED:
            wpa_printf(MSG_DEBUG, "TLSv1: Handshake completed "
                       "successfully");
            conn->state = ESTABLISHED;
            *out_len = 0;

            if (no_appl_data) {
                /* Need to return something to get final TLS ACK. */
                return os_malloc(1);
            }

            return NULL;

        default:
            wpa_printf(MSG_DEBUG, "TLSv1: Unexpected state %d while "
                       "generating reply", conn->state);
            return NULL;
    }
}


u8* tlsv1_client_send_alert(struct tlsv1_client* conn, u8 level,
                            u8 description, size_t* out_len)
{
    u8* alert, *pos, *length;

    wpa_printf(MSG_DEBUG, "TLSv1: Send Alert(%d:%d)", level, description);
    *out_len = 0;

    alert = os_malloc(10);

    if (alert == NULL) {
        return NULL;
    }

    pos = alert;

    /* TLSPlaintext */
    /* ContentType type */
    *pos++ = TLS_CONTENT_TYPE_ALERT;
    /* ProtocolVersion version */
    WPA_PUT_BE16(pos, conn->rl.tls_version ? conn->rl.tls_version :
                 TLS_VERSION);
    pos += 2;
    /* uint16 length (to be filled) */
    length = pos;
    pos += 2;
    /* opaque fragment[TLSPlaintext.length] */

    /* Alert */
    /* AlertLevel level */
    *pos++ = level;
    /* AlertDescription description */
    *pos++ = description;

    WPA_PUT_BE16(length, pos - length - 2);
    *out_len = pos - alert;

    return alert;
}
